An EISDescriptor defines the mapping from a JCA data
structure to a Java object. There are two types of EIS descriptors:

Root - indicates to the EclipseLink runtime that the EIS descriptor's
reference class is a parent class: no other class will reference it by way of
a composite object mapping or composite collection mapping. For an EIS root
descriptor, EIS interactions can be defined to invoke methods on an EIS

Composite - indicates to the EclipseLink runtime that the EIS descriptor's
reference class may be referenced by a composite object mapping or composite
collection mapping

buildFieldValueFromNestedRows(java.util.Vector nestedRows,
java.lang.String structureName,
org.eclipse.persistence.internal.sessions.AbstractSession session)
INTERNAL:
Build and return the appropriate field value for the specified
set of nested rows.

initializeAggregateInheritancePolicy(org.eclipse.persistence.internal.sessions.AbstractSession session)
INTERNAL: This is needed by regular aggregate descriptors * but not by
EIS aggregate descriptors.

boolean

isEISDescriptor()
PUBLIC:
Return if the descriptor maps to an EIS or NoSQL datasource.

requiresInitialization(org.eclipse.persistence.internal.sessions.AbstractSession session)
INTERNAL:
XML descriptors are initialized normally, since they do
not need to be cloned by ESI aggregate mappings.

getInheritancePolicy

PUBLIC:
The inheritance policy is used to define how a descriptor takes part in inheritance.
All inheritance properties for both child and parent classes is configured in inheritance policy.
Caution must be used in using this method as it lazy initializes an inheritance policy.
Calling this on a descriptor that does not use inheritance will cause problems, #hasInheritance() must always first be called.

addDirectMapping

PUBLIC: Add a direct mapping to the receiver. The new mapping specifies
that an instance variable of the class of objects which the receiver
describes maps in the default manner for its type to the indicated
database field.

addDirectMapping

PUBLIC:
Add a direct to node mapping to the receiver. The new mapping specifies that
a variable accessed by the get and set methods of the class of objects which
the receiver describes maps in the default manner for its type to the indicated
database field.

addPrimaryKeyFieldName

public void addPrimaryKeyFieldName(java.lang.String fieldName)

PUBLIC:
Specify the primary key field.
This should be called for each field that make up the primary key.
For EIS XML Descriptors use the addPrimaryKeyField(DatabaseField) API
and supply an org.eclipse.persistence.oxm.XMLField parameter instead of using this method

setSequenceNumberFieldName

public void setSequenceNumberFieldName(java.lang.String fieldName)

PUBLIC:
Set the sequence number field name.
This is the field in the descriptors table that needs its value to be generated.
This is normally the primary key field of the descriptor.
For EIS XML Descriptors use the setSequenceNumberFieldName(DatabaseField) API
and supply an org.eclipse.persistence.oxm.XMLField parameter instead of using this method